% x = G/F and y = X/F
syms x y m l I s b g M;
eqn1 = 1 + m*l*s*s*x == (b*s + (m+M)*s*s)*y;
eqn2 = 1/4*I*s*s*x + m*g*l*x + m*l*l*s*s*x == l*m*s*s*y;
[x,y] = solve(eqn1,eqn2,x,y);
x = simplify(x)
x = collect(x,s)
y = simplify(y)
y = collect(y,s)

simplify(subs(x,{M,m,b,I,l,g},{0.5,0.2,0.1,0.024,0.3,9.8}))
simplify(subs(y,{M,m,b,I,l,g},{0.5,0.2,0.1,0.024,0.3,9.8}))